Problem: What do the following two equations represent? $2x-2y = -4$ $-10x+10y = 0$
Explanation: Putting the first equation in $y = mx + b$ form gives: $2x-2y = -4$ $-2y = -2x-4$ $y = 1x + 2$ Putting the second equation in $y = mx + b$ form gives: $-10x+10y = 0$ $10y = 10x$ $y = 1x + 0$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.